Hybrid ZVS / ZCS-based passive auxiliary soft switching power amplifier

Abstract

The invention discloses a passive auxiliary soft switching power amplifier based on hybrid ZVS (Zero Voltage Switching) / ZCS (Zero Voltage Switching). The passive auxiliary soft switching power amplifier comprises a double-direct-current voltage module, a double-resonant capacitor and resonant inductor passive soft switching network, a midpoint double-path parallel bridge arm, a double-switching tube high-frequency main power output bridge arm, a double-parallel auxiliary capacitor and an LC filtering output network. The passive auxiliary device adopted by the invention is simple, an additional auxiliary switch tube and a driving module are not needed, and the control complexity is greatly reduced; the design that the resonant inductor is connected in series with the midpoint bridge arm avoids the direct connection risk of the bridge arm fundamentally, dead time does not need to be set, and the operation reliability is improved; meanwhile, a hardware condition is created for realizing hybrid ZVS / ZCS for the full-switching tube, so that the switching loss is reduced, the heat loss of the whole machine is reduced due to the low-loss characteristic of the passive network, the heat dissipation design can be simplified, and the service life of the device can be prolonged; and the network structure is simple, small in size and easy to integrate.

Description

A passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS Technical Field

[0001] This invention relates to passive auxiliary soft-switching power amplifiers, and more specifically to a passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS. Background Technology

[0002] In recent years, high-frequency, high-precision power amplifiers have found crucial applications in various fields, including biomedicine, semiconductor manufacturing, communication radar, and industrial testing, thanks to their stable signal amplification capabilities and precise control characteristics. For example, high-frequency, high-precision power amplifiers have been incorporated as core components in tumor electric field therapy equipment, requiring the application of mid-frequency (100-500 kHz), low-intensity (1-3 V / cm) alternating electric fields at high frequencies. One of the key challenges is how to improve conversion efficiency while ensuring the high-frequency, high-precision output of the core power amplifier, thereby enhancing equipment reliability, extending uptime, and mitigating adverse effects caused by equipment weight and heat generation.

[0003] Under these technical requirements, a buffer circuit designed using the resonant principle becomes an effective method to achieve soft switching of switching devices, thereby reducing power loss and improving converter efficiency under high-frequency switching conditions. Existing buffer circuits mostly employ active auxiliary circuits, which present the following problems for high-frequency, high-precision, and high-efficiency applications: 1. High control complexity: Active auxiliary circuits require additional auxiliary switching transistors and dedicated drive modules, necessitating precise timing coordination with the main power switching transistors. Especially in high-frequency scenarios, control delays can easily lead to bridge arm shoot-through risks, increasing system debugging difficulty; 2. A trade-off between efficiency and cost: The introduction of auxiliary switching transistors generates additional conduction and switching losses. Under low-power output conditions, the proportion of losses in the auxiliary circuit increases significantly, actually reducing overall efficiency. Simultaneously, the additional components and control units increase circuit costs; 3. Poor reliability and integration: The multi-switching topology increases circuit failure points. Cooperative failure of the auxiliary and main switches can easily lead to device burnout. Furthermore, the additional auxiliary switches and drive circuits increase circuit size and weight, hindering integration. Summary of the Invention

[0004] The purpose of this invention is to provide a passive auxiliary soft-switching power amplifier based on a hybrid ZVS / ZCS. It employs a passive soft-switching network of dual resonant capacitors and resonant inductors as a passive buffer circuit to achieve soft switching of all high-frequency switching transistors. This effectively reduces the di / dt of the turn-on transient and the du / dt of the turn-off transient, providing zero-current switching (ZCS) or zero-voltage switching (ZVS) for the power semiconductors, thereby reducing switching power losses. Simultaneously, the passive buffer circuit of this invention only includes passive components such as inductors, capacitors, and diodes, resulting in a simple structure that eliminates the need for additional auxiliary switches and complex controls, reducing circuit costs. Furthermore, it fundamentally avoids the risk of bridge arm shoot-through, eliminating the need for dead time and significantly improving the reliability and stability of the converter. Thus, it achieves the invention's objective of high efficiency and high reliability while ensuring high-frequency, high-precision output of the converter.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS, the passive auxiliary soft-switching power amplifier includes dual DC voltage modules, a passive soft-switching network of dual resonant capacitors and resonant inductors, a midpoint dual parallel bridge arm, a dual-switch high-frequency main power output bridge arm, dual parallel auxiliary capacitors and an LC filter output network;

[0007] The dual DC voltage module is used to provide input voltage;

[0008] The passive soft-switching network of dual resonant capacitors and resonant inductors is connected to dual DC voltage modules, a midpoint dual-parallel bridge arm, and a dual-switch high-frequency main power output bridge arm to suppress the voltage rise rate when the switches are turned off and the current rise rate when they are turned on, thereby achieving soft switching. The passive soft-switching network of dual resonant capacitors and resonant inductors includes a resonant inductor. First resonant capacitor Second resonant capacitor First clamping diode Second clamping diode Third clamping diode Fourth clamping diode The first clamping diode connected in sequence Second clamping diode Third clamping diode Fourth clamping diode The first clamping diode is connected in parallel across the two ends of the dual-switch high-frequency main power output bridge arm. The cathode is connected to the positive terminal of the dual DC voltage module, and the fourth clamping diode... The anode of the resonant inductor is connected to the negative terminal of the dual DC voltage module; The first end is connected to the connection point of the two DC power supplies of the dual DC voltage module, and its second end is connected to the second clamping diode. anode, third clamping diode The cathode and midpoint of the dual-path parallel bridge arm are connected to the input terminals; the first clamping diode... The anode and the first resonant capacitor The first end is connected; the fourth clamping diode cathode and second resonant capacitor The first end is connected to the first resonant capacitor. Second resonant capacitor The second end of each capacitor is connected to the input end of the LC filter output network; the passive soft-switching network of the dual resonant capacitor and resonant inductor is connected to the first resonant capacitor. Second resonant capacitor The charging and discharging process provides ZCS turn-on or ZVS turn-on and turn-off conditions for the switching transistors in the midpoint dual-parallel bridge arm and the dual-switch high-frequency main power output bridge arm. At the same time, the resonant inductor current clamps the voltage of the main power switching transistor to 0 when it is turned on, thereby achieving ZVS turn-on of the main power switching transistor.

[0009] The output terminal of the midpoint dual-parallel bridge arm is connected to the dual-switch high-frequency main power output bridge arm, forming a discharge circuit for the passive soft-switching network of dual resonant capacitors and resonant inductors, and providing a freewheeling path when the main switch of the dual-switch high-frequency main power output bridge arm is turned off. The input terminal of the dual-switch high-frequency main power output bridge arm is connected to dual DC voltage modules, and the output terminal is connected to an LC filter output network. By controlling the conduction and turn-off of the main power switch, dual-power bipolar inversion is achieved, and a high-frequency square wave is output to control the voltage change at the load end. The dual parallel auxiliary capacitors are connected in parallel across the two ends of the main power switch, and are used to resonate with the resonant inductor before the main power switch is turned on, so that the voltage across the main power switch is clamped to zero before it is turned on to achieve zero-voltage turn-on. The LC filter output network is used to filter the high-frequency square wave output by the dual-switch high-frequency main power output bridge arm and output a medium-frequency AC voltage.

[0010] Furthermore, the dual DC voltage module includes an upper input DC power supply. and the lower input DC power supply ;

[0011] The upper end inputs DC power. The positive terminal and the first clamping diode The cathode is connected to the terminal, and its negative terminal is connected to the DC power input at the lower end. The positive terminal and the resonant inductor The first end is connected;

[0012] The lower end inputs a DC power supply. The positive terminal is connected to the upper input DC power supply. negative terminal and resonant inductor The first end is connected, and its negative terminal is connected to the fourth clamping diode. The anode phase is connected.

[0013] Furthermore, the midpoint dual-path parallel bridge arm includes a second power switch. Third power switching transistor First freewheeling diode Second freewheeling diode ;

[0014] Second power switch The source and resonant inductor The second end and the third power switch The drain of the diode is connected to the first freewheeling diode. Cathode connection; the first freewheeling diode anode and second freewheeling diode The cathode is connected to the input terminal of the LC filter output network; the second freewheeling diode anode and third power switch The source poles are connected.

[0015] Furthermore, the dual-switch high-frequency main power output bridge arm includes a first power switch transistor connected in series between the positive and negative terminals of the dual DC voltage modules. and the fourth power switch ;

[0016] The first power switch The drain of the first clamping diode is connected to the positive terminal of the dual DC voltage module. The cathode is connected to the source of the first resonant capacitor. The second end, the output terminal of the midpoint dual-parallel bridge arm, and the second resonant capacitor The second end, the fourth power switch The drain of the filter is connected to the input of the LC filter output network;

[0017] The fourth power switch The source and the negative terminal of the dual DC voltage module, the fourth clamping diode The anode phase is connected.

[0018] Furthermore, the first clamping diode The cathode and the first power switch The drain is connected, and the fourth clamping diode is connected. The anode and the fourth power switch The source poles are connected.

[0019] Furthermore, the dual parallel auxiliary capacitors include a first parallel auxiliary capacitor. Second parallel auxiliary capacitor First parallel auxiliary capacitor Second parallel auxiliary capacitor They are connected in parallel to the first power switch. Fourth power switching transistor The two ends.

[0020] Furthermore, the LC filter output network includes a filter inductor. and filter capacitor ;

[0021] The filter inductor The first end is connected to the output terminal of the dual-switch high-frequency main power output bridge arm, and the other end is connected to the output filter capacitor. The first end; the filter capacitor The second end is connected to the connection point of the two DC power supplies of the dual DC voltage module; the filter capacitor The two ends serve as the positive and negative terminals of the output high-frequency AC voltage, respectively, and are connected to the load. in parallel.

[0022] Furthermore, the connection point of the two DC power supplies of the dual DC voltage module is grounded.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] First, the passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS of this invention has a low complexity in its power amplifier control method, eliminating the need for additional auxiliary switching transistors and corresponding drive modules, thus effectively simplifying the control circuit. Simultaneously, the resonant inductor is connected in series in the midpoint bridge arm, eliminating the risk of bridge arm shoot-through and freeing the circuit from dead-time limitations, significantly improving the reliability and stability of the converter.

[0025] Secondly, the passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS of this invention features a passive soft-switching network consisting of a dual resonant capacitor and a resonant inductor. This network comprises one inductor, two capacitors, and four diodes, resulting in a simple selection of passive auxiliary components, a streamlined structure, and advantages such as small size and easy integration. Compared to traditional active buffer circuits, this passive auxiliary network significantly reduces power loss, thereby improving the overall operating efficiency of the power amplifier.

[0026] Third, the passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS of this invention provides soft-switching hardware circuit conditions for all switching transistors through a passive buffer unit, reducing switching losses of the switching transistors. Furthermore, the passive auxiliary network itself has low losses, significantly reducing overall heat loss. This lowers the design requirements for the heat dissipation system, eliminating the need for high-power heat dissipation devices and simplifying the heat dissipation structure; it also extends the service life of the equipment. Attached Figure Description

[0027] Figure 1 is a topology diagram of a passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to the present invention.

[0028] Figure 2 is a timing diagram of the power amplifier of the present invention, including the drive signal, switching transistor current, resonant inductor current, filter inductor current, voltage across the switching transistor, and resonant capacitor voltage.

[0029] Figure 3 is a circuit topology mode diagram of the power amplifier of the present invention; wherein (a)-(f) correspond to working mode 1 to working mode 6 respectively. Detailed Implementation

[0030] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0031] Referring to Figure 1, this embodiment of the invention discloses a passive auxiliary soft-switching power amplifier based on a hybrid ZVS / ZCS architecture. This passive auxiliary soft-switching power amplifier includes dual DC voltage modules 1, a passive soft-switching network of dual resonant capacitors and resonant inductors 2, a midpoint dual-parallel bridge arm 3, a dual-switch high-frequency main power output bridge arm 4, dual parallel auxiliary capacitors 5, and an LC filter output network 6. This passive auxiliary soft-switching power amplifier consists of a first power switch transistor... Second power switching transistor Third power switching transistor Fourth power switching transistor First freewheeling diode Second freewheeling diode First clamping diode Second clamping diode Third clamping diode Fourth clamping diode Resonant inductor First resonant capacitor Second resonant capacitor First parallel auxiliary capacitor Second parallel auxiliary capacitor Filter inductor Filter capacitor Composition. The structural composition and connection methods of each functional module are as follows:

[0032] (1) Dual DC voltage module 1 provides input voltage for the power amplifier The dual DC voltage module includes:

[0033] DC power input at the top Its positive terminal is connected to the first clamping diode. cathode, first power switch The drain of the device is connected to the cathode, and the lower end is connected to the DC power supply input. The positive terminal and the resonant inductor One end is connected; and,

[0034] DC power input at the lower end Its positive terminal is connected to the DC power supply input at the upper end. negative terminal and resonant inductor One end is connected to the fourth clamping diode, and its negative terminal is connected to the fourth clamping diode. anode, fourth power switch The source poles are connected.

[0035] (2) The passive soft-switching network 2 using a dual resonant capacitor and resonant inductor is used to implement soft switching for all switching transistors. The passive soft-switching network using a dual resonant capacitor and resonant inductor includes:

[0036] First clamping diode Its cathode is connected to the upper end of the DC power supply. The positive terminal, the first power switch transistor Its drain is connected to the second clamping diode, and its anode is connected to the second clamping diode. cathode, first resonant capacitor One end is connected; and,

[0037] First resonant capacitor One end of it is connected to the first clamping diode. anode, second clamping diode The cathode is connected to the first diode, and the other end is connected to the first freewheeling diode. Second freewheeling diode First power switching transistor The source, the fourth power switch Drain and second resonant capacitor one end and the filter inductor One end is connected; and,

[0038] Second clamping diode Its cathode and the first clamping diode anode, first resonant capacitor One end is connected to the resonant inductor, and its anode is connected to the resonant inductor. One end, third clamping diode cathode, second power switch The source and the third power switch The drain is connected; and,

[0039] Resonant inductor One end of it is connected to the upper input DC power supply. The negative terminal and the lower end input DC power supply One end is connected to the positive terminal, and the other end is connected to the second clamping diode. anode, third clamping diode cathode, second power switch The source and the third power switch The drain is connected; and,

[0040] Third clamping diode Its cathode and resonant inductor Second clamping diode anode, second power switch The source and the third power switch The drain is connected to the anode of the fourth clamping diode. cathode, second resonant capacitor One end is connected; and,

[0041] Second resonant capacitor One end of it is connected to the third clamping diode. anode, fourth clamping diode The cathode is connected to the first terminal, and the other end is connected to the second freewheeling diode. First freewheeling diode Fourth power switching transistor The drain of the first power switch transistor The source and the first resonant capacitor one end and the filter inductor One end is connected; and,

[0042] Fourth clamping diode Its cathode third clamping diode anode, second resonant capacitor One end is connected to the DC power input at the lower end, and its anode is connected to the DC power input at the lower end. The negative terminal, the fourth power switch The source poles are connected.

[0043] First resonant capacitor Discharge, third power switch The current rises slowly to achieve ZCS conduction, and the fourth power switch is activated. Slow voltage rise achieves ZVS turn-off; first resonant capacitor Charging, third power switch Slow voltage rise achieves ZVS turn-off; second resonant capacitor Discharge, second power switch The current rises slowly to achieve ZCS conduction, and the first power switch transistor... Slow voltage rise achieves ZVS turn-off; second resonant capacitor Charging, second power switch The voltage rises slowly to achieve ZVS turn-off; the resonant inductor currents are respectively at the first power switch. and the fourth power switch When turned on, its voltage is clamped to 0 to achieve ZVS turn-on of the switching transistor.

[0044] (3) The midpoint dual-path parallel bridge arm 3 is used to form a discharge circuit for the resonant capacitor when the main switch of the dual-switch high-frequency main power output bridge arm is turned off, and at the same time provides a freewheeling path. The midpoint dual-path parallel bridge arm includes:

[0045] Second power switch Its source is the resonant inductor One end, the second clamping diode anode, third clamping diode cathode, third power switch The drain of the diode is connected to the first freewheeling diode. Cathode connection; and,

[0046] First freewheeling diode Its cathode and the second power switch The drain of the capacitor is connected to the anode of the capacitor, and its anode is connected to the first resonant capacitor. One end, the second freewheeling diode cathode, first power switch Source and filter inductor One end, the fourth power switch Drain and second resonant capacitor One end is connected; and,

[0047] Second freewheeling diode Its cathode and the first resonant capacitor One end, the first freewheeling diode anode, first power switch Source and filter inductor One end, the fourth power switch Drain and second resonant capacitor One end is connected to the third power switch, and its anode is connected to the third power switch. The source poles are connected; and,

[0048] Third power switch Its source is connected to the second freewheeling diode. The anode, its drain resonant inductance One end, the second clamping diode anode, third clamping diode cathode, second power switch The source poles are connected.

[0049] First freewheeling diode Second power switching transistor Forming the second resonant capacitor The discharge circuit and filter inductor Negative current freewheeling channel, second freewheeling diode Third power switching transistor Forming the first resonant capacitor The discharge circuit and filter inductor Forward current freewheeling path.

[0050] (4) The dual-switch high-frequency main power output bridge arm 4 is used to control the first power switch. Fourth power switching transistor Turning the transistors on and off enables main power output. The dual-switch high-frequency main power output bridge arm includes:

[0051] First power switch transistor Its drain is connected to the upper input DC power supply. The positive terminal, the first clamping diode The cathode is connected to the source of the first resonant capacitor. One end, the first freewheeling diode anode, second freewheeling diode cathode, second resonant capacitor One end, the fourth power switch Drain and filter inductor One end is connected; and,

[0052] Fourth power switch Its drain is connected to the first power switch. The source and the first resonant capacitor One end, the first freewheeling diode anode, second freewheeling diode cathode, second resonant capacitor one end and the filter inductor One end is connected to the DC power supply input at the lower end, and its source is connected to the DC power supply input at the lower end. The negative terminal, the fourth clamping diode The anode phase is connected.

[0053] (5) The dual parallel auxiliary capacitor 5 is used to resonate with the resonant inductor before the main power switch is turned on, so that the first power switch... Fourth power switching transistor The voltage across the terminals is clamped to zero before turn-on to achieve zero-voltage turn-on. The dual parallel auxiliary capacitors include:

[0054] First parallel auxiliary capacitor One end is connected to the first power switch transistor Drain diode, first clamping diode Cathode, upper end input DC power The positive terminal is connected to the first power switch transistor, and the other end is connected to the positive terminal. The source, the fourth power switch drain, first resonant capacitor One end, the first freewheeling diode anode, second freewheeling diode cathode, second resonant capacitor One end, the second parallel auxiliary capacitor One end, filter capacitor One end;

[0055] Second parallel auxiliary capacitor One end is connected to the fourth power switch. The source diode, the fourth clamping diode The anode and the lower end input DC power supply The negative terminal is connected to the fourth power switch. The drain of the first power switch transistor The source and the first resonant capacitor One end, the first freewheeling diode anode, second freewheeling diode cathode, second resonant capacitor One end, the first parallel auxiliary capacitor One end, filter capacitor One end.

[0056] (6) The LC filter output network 6 is used to filter the energy transmitted by the dual-switch high-frequency main power output bridge arm and output intermediate frequency AC voltage. The LC filter output network includes:

[0057] Filter inductor One end is connected to the first power switch transistor The source and the first resonant capacitor One end, the first freewheeling diode anode, second freewheeling diode cathode, second resonant capacitor One end, the fourth power switch The other end is connected to the output filter capacitor. One end;

[0058] Filter capacitor One end is connected to the filter inductor. One end is connected to the upper input DC power supply, and the other end is connected to the upper input DC power supply. The negative terminal and the lower end input DC power supply The positive terminal. Filter capacitor. The two ends serve as the positive and negative terminals of the output high-frequency AC voltage, which are also the positive and negative terminals of the intermediate-frequency AC voltage of the soft-switching T-type power amplifier of this invention, used for connection with the load. in parallel.

[0059] The power amplifier designed in this invention employs fundamental frequency modulation. Dual DC voltage modules provide DC voltage to the power amplifier. A passive soft-switching network consisting of dual resonant capacitors and inductors is connected to the dual DC voltage modules, the midpoint dual-parallel bridge arm, and the dual-switch high-frequency main power output bridge arm. This network is used to suppress the voltage rise rate during switch turn-off and the current rise rate during switch turn-on to achieve soft switching. The input terminal of the midpoint dual-parallel bridge arm is connected to the passive soft-switching network, and the output terminal of the midpoint dual-parallel bridge arm is connected to the dual-switch high-frequency main power output bridge arm. The arm connection forms the discharge circuit of the passive soft-switching network of the dual resonant capacitor and resonant inductor, and provides a freewheeling path when the main switch of the dual-switch high-frequency main power output bridge arm is turned off. The input terminal of the dual-switch high-frequency main power output bridge arm is connected to the dual DC voltage module, and the output terminal is connected to the LC filter output network to realize dual-power bipolar inversion and output a high-frequency square wave for load voltage changes. The two parallel auxiliary capacitors are connected in parallel across the two ends of the main power switch to resonate with the resonant inductor before the main power switch is turned on, so that the first power switch... Fourth power switching transistor The voltage at both ends is clamped to zero before turn-on to achieve zero-voltage turn-on; the LC filter output network is used to filter the high-frequency square wave output of the dual-switch high-frequency main power output bridge arm and output the intermediate frequency AC voltage.

[0060] This invention reduces the rate of rise of voltage and current during the turn-on and turn-off of the switching transistors through a passive soft-switching network of dual resonant capacitors and resonant inductors, thereby achieving soft switching for all power switching transistors. The working principle and operating modes of the soft-switching converter of this invention are analyzed in detail below using ideal signal waveforms in Figure 2 and modal diagrams 3 (a)-(f).

[0061] Operating mode 1: The circuit shown in Figure 3(a) corresponds to the circuit shown in Figure 2. The first power switch in the range , Third power switch Second freewheeling diode Turn on, second power switch and the fourth power switch Off, DC power input at the upper end Added to the resonant inductor Both ends. Through the third power switch Second freewheeling diode Continuous flow, Within the interval, Flow through the first power switch Clamp its voltage to 0. Descending to and equal, Rise to 0, in First power switch at moment ZVS is enabled. Within the interval, Drop to 0, Rise to and If they are equal, this phase ends.

[0062] Operating mode 2: The circuit shown in Figure 3(b) corresponds to the circuit shown in Figure 2. The first power switch in the range Third power switching transistor and the third clamping diode Turn on, second power switch Fourth power switching transistor Turn off. DC power is input from the top. Second resonant capacitor Resonant inductor Third clamping diode and the first power switch The resonant circuit initially consists of the second resonant capacitor. Charging, and simultaneously the second power switch A slow voltage rise achieves ZVS shutdown. The resonance rises to its peak value and then drops to 0; the second resonant capacitance... Resonant charging to input voltage This phase is now complete.

[0063] Operating mode 3: The circuit shown in (c) of Figure 3 corresponds to the circuit shown in Figure 2. The first power switch in the range Third power switching transistor Turn on, second power switch Fourth power switching transistor Turn off. Second resonant capacitor. Resonant inductor and the third clamping diode Disconnected from the main circuit, the second resonant capacitor Voltage remains at , Keep it at 0. Follow Rising. In At that moment, the first power switch transistor Shut down; this phase ends.

[0064] Operating mode 4: The circuit shown in (d) of Figure 3 corresponds to the circuit shown in Figure 2. Interval, second power switch First freewheeling diode Third power switching transistor Second freewheeling diode Turn on, first power switch transistor Fourth power switching transistor Turn off. Second resonant capacitor. Through the first freewheeling diode Second power switching transistor Resonant inductor DC power supply input at the lower end Fourth clamping diode The resonant circuit composed of the second and third resonant capacitors discharges, and the voltage is from Slowly decrease to zero. The resonance rises to its peak value and then drops to 0. First power switch. Voltage at the second resonant capacitor The discharge slowly rises to Achieve ZVS turn-off. First parallel auxiliary capacitor. Charging, second parallel auxiliary capacitor Discharge, when the second resonant capacitor This stage ends when the discharge reaches 0.

[0065] Operating mode 5: The circuit shown in (e) of Figure 3 corresponds to the circuit shown in Figure 2. In this range, all power switches are off, and a DC power supply is input at the upper end. Resonant inductor Third power switching transistor Second freewheeling diode and the first parallel auxiliary capacitor Forming the first parallel auxiliary capacitor The resonant discharge circuit has a DC power input at its lower end. Resonant inductor Third power switching transistor Second freewheeling diode Second parallel auxiliary capacitor Forming a second parallel auxiliary capacitor The resonant charging circuit. In At that moment, the first parallel auxiliary capacitor Discharge to 0, second parallel auxiliary capacitor Charged to , The resonance rises to its peak value and then drops to 0, at which point this phase ends.

[0066] Operating mode 6: The circuit shown in (f) of Figure 3 corresponds to the circuit shown in Figure 2. In this range, all power switches are off, and a DC power supply is input at the upper end. First parallel auxiliary capacitor First freewheeling diode Second power switching transistor and resonant inductor Forming the first parallel auxiliary capacitor The resonant charging circuit has a DC power input at the lower end. Second parallel auxiliary capacitor First freewheeling diode Second power switching transistor and resonant inductor Forming a second parallel auxiliary capacitor The charging circuit. In At that moment, the fourth power switch Open, Resonance to a negative value indicates the fourth power switch. This creates the conditions for ZVS to be enabled, and this phase ends.

[0067] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0068] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS, characterized in that, The passive auxiliary soft-switching power amplifier includes dual DC voltage modules, a passive soft-switching network of dual resonant capacitors and resonant inductors, a midpoint dual-parallel bridge arm, a dual-switch high-frequency main power output bridge arm, dual parallel auxiliary capacitors, and an LC filter output network. The dual DC voltage modules provide the input voltage. The passive soft-switching network of dual resonant capacitors and resonant inductors is connected to the dual DC voltage modules, the midpoint dual-parallel bridge arm, and the dual-switch high-frequency main power output bridge arm, and is used to suppress the voltage rise rate when the switching transistors are turned off and the current rise rate when they are turned on to achieve soft switching. The passive soft-switching network of dual resonant capacitors and resonant inductors includes a resonant inductor. First resonant capacitor Second resonant capacitor First clamping diode Second clamping diode Third clamping diode Fourth clamping diode The first clamping diode connected in sequence Second clamping diode Third clamping diode Fourth clamping diode The first clamping diode is connected in parallel across the two ends of the dual-switch high-frequency main power output bridge arm. The cathode is connected to the positive terminal of the dual DC voltage module, and the fourth clamping diode... The anode of the resonant inductor is connected to the negative terminal of the dual DC voltage module; The first end is connected to the connection point of the two DC power supplies of the dual DC voltage module, and its second end is connected to the second clamping diode. anode, third clamping diode The cathode and midpoint of the dual-path parallel bridge arm are connected to the input terminals; the first clamping diode... The anode and the first resonant capacitor The first end is connected; the fourth clamping diode cathode and second resonant capacitor The first end is connected to the first resonant capacitor. Second resonant capacitor The second end of each capacitor is connected to the input end of the LC filter output network; the passive soft-switching network of the dual resonant capacitor and resonant inductor is connected to the first resonant capacitor. Second resonant capacitor The charging and discharging process provides ZCS turn-on or ZVS turn-on / turn-off conditions for the switching transistors in the midpoint dual-parallel bridge arm and the dual-switch high-frequency main power output bridge arm. Simultaneously, the resonant inductor current clamps the voltage of the main power switch to 0 when it is turned on, achieving ZVS turn-on for the main power switch. The output terminal of the midpoint dual-parallel bridge arm is connected to the dual-switch high-frequency main power output bridge arm, forming a discharge circuit for the passive soft-switching network of dual resonant capacitors and resonant inductors, and providing a freewheeling path when the main switch of the dual-switch high-frequency main power output bridge arm is turned off. The dual-switch high-frequency main power output bridge... The input end of the arm is connected to a dual DC voltage module, and the output end is connected to an LC filter output network. By controlling the on and off of the main power switch, a dual-power bipolar inverter is achieved, outputting a high-frequency square wave to control the load voltage change. The dual parallel auxiliary capacitors are connected in parallel across the main power switch to resonate with the resonant inductor before the main power switch is turned on, so that the voltage across the main power switch is clamped to zero before it is turned on to achieve zero-voltage turn-on. The LC filter output network is used to filter the high-frequency square wave output from the dual-switch high-frequency main power output bridge arm and output a medium-frequency AC voltage.

2. The passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to claim 1, characterized in that, The dual DC voltage module includes an upper input DC power supply. and the lower input DC power supply The upper end inputs a DC power supply. The positive terminal and the first clamping diode The cathode is connected to the terminal, and its negative terminal is connected to the DC power input at the lower end. The positive terminal and the resonant inductor The first end is connected; the lower end is input with DC power. The positive terminal is connected to the upper input DC power supply. negative terminal and resonant inductor The first end is connected, and its negative terminal is connected to the fourth clamping diode. The anode phase is connected.

3. The passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to claim 1, characterized in that, The midpoint dual-parallel bridge arm includes a second power switch. Third power switching transistor First freewheeling diode Second freewheeling diode The second power switch The source and resonant inductor The second end and the third power switch The drain of the diode is connected to the first freewheeling diode. Cathode connection; the first freewheeling diode anode and second freewheeling diode The cathode is connected to the input terminal of the LC filter output network; the second freewheeling diode anode and third power switch The source poles are connected.

4. The passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to claim 1, characterized in that, The dual-switch high-frequency main power output bridge arm includes a first power switch transistor connected in series between the positive and negative terminals of the dual DC voltage modules. and the fourth power switch The first power switch The drain of the first clamping diode is connected to the positive terminal of the dual DC voltage module. The cathode is connected to the source of the first resonant capacitor. The second end, the output terminal of the midpoint dual-parallel bridge arm, and the second resonant capacitor The second end, the fourth power switch The drain of the fourth power switch is connected to the input of the LC filter output network; The source and the negative terminal of the dual DC voltage module, the fourth clamping diode The anode phase is connected.

5. The passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to claim 4, characterized in that, First clamping diode The cathode and the first power switch The drain is connected, and the fourth clamping diode is connected. The anode and the fourth power switch The source poles are connected.

6. The passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to claim 4, characterized in that, The dual parallel auxiliary capacitors include a first parallel auxiliary capacitor. Second parallel auxiliary capacitor First parallel auxiliary capacitor Second parallel auxiliary capacitor Connected in parallel to the first power switch transistor Fourth power switching transistor The two ends.

7. The passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to claim 1, characterized in that, The LC filter output network includes a filter inductor. and filter capacitor The filter inductor The first end is connected to the output terminal of the dual-switch high-frequency main power output bridge arm, and the other end is connected to the output filter capacitor. The first end; the filter capacitor The second end is connected to the connection point of the two DC power supplies of the dual DC voltage module; the filter capacitor The two ends serve as the positive and negative terminals of the output high-frequency AC voltage, respectively, and are connected to the load. in parallel.

8. The passive auxiliary soft-switching power amplifier based on hybrid ZVS / ZCS according to claim 1, characterized in that, The connection point of the two DC power supplies of the dual DC voltage module is grounded.

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